Operating insert for a resectoscope with sealing means

ABSTRACT

An operating insert to be passed through a resectoscope shaft comprises a channel for an axially displaceable cutting loop which extends parallel to an optical system through the operating insert. The cutting loop has branches secured within a tube and merging at their proximal ends into an electrode stem which extends beyond the shaft as far as an electrode carrier. An annular cylindrical sealing element of plastics material or the like is secured on the stem or on the inner side of the channel and bears via sealing projections against the inner surface of the cutting loop so as to prevent the passage of fluid to the proximal end of the channel while allowing axial movement of the stem and the tube within the channel.

BACKGROUND TO THE INVENTION

The invention is based on a resectoscope of the type comprising anoperating insert arranged within a shaft and receiving therein anoptical system and a channel for an axially displaceable cutting loop.The cutting loop has two proximally extending loop branches which aresecured within a thin-walled tube and have proximal ends which mergeinto an electrode stem which may be releasably secured in an electrodecarrier.

Because the proximal end of the cutting loop which is to be suppliedwith high-frequency current extends partially clear of the operatinginsert to the electrode carrier, a small quantity of flushing liquidpresent in the bladder may emerge in an uncontrolled manner at the endof the channel situated in the operating insert and receiving the stemof the cutting loop. Consequently the surgeon, whose face is positionedin direct proximity to the liquid outlet point during observation of theresection, is exposed to a risk of infection.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to prevent the emergence offlushing liquid at the proximal end of the channel receiving the stem ofthe cutting loop in the case of resectoscopes of the aforementionedtype.

This object is achieved in accordance with the invention, in that asealing element, preferably a plastics material element of cylindricalform, is fastened to the stem or on the inner side of the channel, andhas sealing projections which bear against the inner side of the channelor against the outer periphery of the tube or the stem of the operatinginsert in a sealing manner. Preferably, the distal end of the sealingelement engages with the tube which secures the loop branches, and has acylindrical constriction provided with sealing projections such as lipsor pins which bear in a sealing manner against the inner surface of thechannel receiving the stem of the cutting loop, without increasing thefrictional resistance to axial displacement of the cutting loop.

Alternatively, the cylindrical sealing ring of plastics material isfastened to the inner surface of the channel and has at least oneinwardly directed lip or radially inwardly directed pins for sealingcontact with the tube or the stem of the cutting electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects and advantages of the invention will become apparentfrom the following detailed description when read with reference to theaccompanying drawings which illustrate preferred embodiments of theinvention.

In the drawings:

FIG. 1 shows a schematic view of an operating insert showing theposition of the sealing element;

FIGS. 2 to 6 show the views of the operating insert with variousembodiments of the sealing element;

FIG. 7 shows the coupling cone of the operating insert with the sealingelement of the first embodiment shown in FIG. 2;

FIG. 8 shows a cutting loop, incorporating a sealing element;

FIGS. 9 to 13 show partial views of the cutting loop according to FIG.8, illustrating different sealing elements.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The resectoscope comprises a shaft which is not illustrated, anoperating insert 1 into which an optical system 2 may be releasablyinserted and a channel 4 for receiving a cutting loop or rather itsproximal stem. The operating insert is provided at its proximal end withan axially displaceable electrode carrier 5. The cutting loop 6 to 10comprises the loop member 6, of which the two branches 7 extend througha tube 8 and are secured in the tube 8. These branches 7 merge at theproximal end of the tube 8 into a stem 9 which is connected to thecarrier 5 and may be connected to a high-frequency generator via aconnecting lead.

As shown in FIGS. 2 to 6, a sealing element 10 formed from anappropriate plastics material is provided, said element being ofcylindrical form and engaging in a fixed manner at its distal end withthe tube 8. As shown in FIGS. 9 to 12, this sealing element 10 isprovided with a cylindrical constriction 11. In the embodiment shown inFIG. 9 the constriction 11 is provided with transversely slottedencircling sealing lips 12 which project beyond the circumference of thetube 8 and bear in a sealing manner against the inner surface of thechannel 4.

In an alternative embodiment shown in FIG. 10, the lips 13 arepart-circular and arranged in a staggered manner such that their endslie close to one another and overlap each other.

Alternatively, in FIG. 11, the constriction 11 is provided withprojections 14 in the form of pins extending radially beyond thecircumference of the tube 8, which lie close to each other and areplaced in mutual contact by deformation when the cutting loop isinserted into the channel 4.

Alternatively, in FIG. 12, the constriction 11 is provided with oneannular lip 15 only, which forms the seal in the channel 4 of theoperating insert.

Alternatively, in FIG. 13, the sealing element 10a has the distal endalso secured in the tube 8 and the proximal end formed as a sealingannular lip 16.

By contrast to FIGS. 9 to 13, the cylindrical sealing element 10 may befastened to the inner surface 4a of the channel 4, so that the lips 12,13, the pins 14 or the lips 15 and 16 are directed inwards radially andare placed in sealing contact at the distal end of the channel 4 againstthe outer periphery of the tube 8 securing the branches 7 of the cuttingloop.

As shown in FIG. 7, the sealing element 10 may also be arranged at theproximal end of the channel 4.

The embodiments according to FIGS. 2 to 6 have the advantage that thecutting loops produced until now and available commercially may be usedwithout modification.

Since cutting loops may be considered as disposable, the embodimentaccording to FIGS. 9 to 13 may be more advantageous, since the seal isthen assured throughout the period of operation of the insert.

What is claimed is:
 1. An operating insert for a resectoscope, having alongitudinal channel therethrough with proximal and distal ends, anelongate electrode stem extending from an electrode carrier into saidchannel at a proximal end thereof, a tube extending within said channeland a cutting loop projecting from the distal end of said channel, saidcutting loop having a pair of branches which are secured in said tubeand merge into said electrode steam at their proximal ends, whereinsealing means are provided within said channel, said sealing meanshaving radially extending projections which bear against one of saidtube, said stem or said channel and allowing axial movement of said stemand said tube within said channel but preventing the passage of fluid tothe proximal end of said channel.
 2. An operating insert as claimed inclaim 1 wherein the sealing means comprises a cylindrical sealingelement which is mounted on a proximal end of the tube, the sealingelement having projections which bear against the inner surface of thechannel.
 3. An operating insert as claimed in claim 1, wherein thesealing means comprises a cylindrical sealing element which is mountedon the inner surface of the channel, the sealing element havingprojections which extend radially inwardly.
 4. An operating insert asclaimed in claim 3, wherein said cylindrical sealing element ispositioned so that its projections bear against the outer surface of thetube.
 5. An operating insert as claimed in claim 3, wherein saidcylindrical sealing element is positioned so that its projections bearagainst the outer surface of the stem.
 6. An operating insert as claimedin claim 2, wherein the sealing element is of plastics material and hasan annular constriction on which the projections are provided, theprojections comprising encircling sealing lips which are transverselyslotted.
 7. An operating insert as claimed in claim 2, wherein thesealing element is of plastics material and has an annular constrictionon which the projections are provided, the projections comprisingsealing lips which form partial rings, with mutually overlapping endregions.
 8. An operating insert as claimed in claim 2, wherein thesealing element is of plastics material and has an annular constrictionon which the projections are provided, the projections comprisingclosely spaced radially extending pins.
 9. An operating insert asclaimed in claim 3 wherein the sealing element is of plastics materialand has an annular constriction on which the projections are provided,the projections comprising encircling sealing lips which aretransversely slotted.
 10. An operating insert as claimed in claim 3wherein the sealing element is of plastics material and has an annularconstriction on which the projections are provided, the projectionscomprising sealing lips which form partial rings, having mutuallyoverlapping end regions.
 11. An operating insert as claimed in claim 3wherein the sealing element is of plastics material and has an annularconstriction on which the projections are provided, the projectionscomprising closely spaced radially extending pins.
 12. A resectoscopewhich comprises, in combination, a resectoscope shaft and an operatinginsert insertable within said shaft of said resectoscope, said insertcomprising a longitudinal channel therethrough with proximal and distalends, an elongate electrode stem extending from an electrode carrierinto said channel at a proximal end thereof, a tube extending withinsaid channel and a cutting loop projecting from the distal end of saidchannel, said cutting loop having a pair of branches which are securedin said tube and merge into said electrode stem at their proximal ends,wherein sealing means are provided within said channel, said sealingmeans having radially extending projections which bear against one ofsaid tube, said stem or said channel and allowing axial movement of saidstem and said tube within said channel but preventing the passage offluid to the proximal end of said channel.